Aluminium profile cnc build

[JAZZCNC]

Yes Sorry I didn't see this thread at all.!!

The machine design you are thinking to build is very similair to routers I build. I can tell you without doubt that you will need stronger than 80x45 to give the cutting area want at this length. 120 x 80 is what i'd use or at minimum 80 x 80.
With correct profile you won't need middle leg and infact you can't have middle legs with this design because of the cross brace between gantry.

The base will need at least one more support. Cross bracing isn't strictly required because the bed base forms part of the structure but it wouldn't hurt having some just to hold resonably square.